No clinical difference between fixed- and mobile-bearing cruciate-retaining total knee arthroplasty: a prospective randomized study

PURPOSE

It is hypothesized that mobile polyethylene bearings in total knee arthroplasty (TKA) may confer benefits with regard to range of motion and have improved clinical outcome scores in comparison with an arthroplasty with a fixed-bearing design. Our study compares clinical outcomes between patients who undergo TKA with either a rotating platform or fixed bearing using a posterior cruciate-retaining design.

METHODS

Three hundred and thirty-one patients were randomized to receive either a rotating-platform (161 patients) or a fixed-bearing (170 patients) implant. All patients were assessed pre-operatively and at 1 and 2 years post-operatively using standard tools (range of movement, Oxford Knee Score, American Knee Society Score, SF12 and Patella Score).

RESULTS

There was no difference in pre- to 2-year post-operative outcomes between the groups with regard to improvement in range of motion (10° ± 16 vs. 9° ± 15), improvement in Oxford Knee Score (-17.6 ± 9.9 vs. -19.1 ± 8.4), improvement in American Knee Society Score (49.5 ± 24.7 vs. 50.7 ± 21.0), function (23.6 ± 19.6 vs. 25.0 ± 22.5) and pain (34.9 ± 16.2 vs. 35.8 ± 14.1) subscores, improvement in SF12 Score (10.0 ± 16.3 vs. 12.3 ± 15.8) or improvement in Patella Score (9.7 ± 7.4 vs. 10.6 ± 7.1).

CONCLUSION

No difference was demonstrated in clinical outcome between patients with a rotating-platform and fixed-bearing posterior cruciate-retaining TKA at 2-year follow-up.

LEVEL OF EVIDENCE

I.

Utility of a Paediatric Bleeding Questionnaire as a screening tool for von Willebrand disease in apparently healthy children

von Willebrand disease (VWD), an inherited bleeding disorder caused by deficiency or dysfunction of von Willebrand factor (VWF) is diagnosed when a personal and often a family history of excessive mucocutaneous bleeding is present along with abnormal laboratory studies. An accurate assessment of haemorrhagic symptoms is key in suspecting VWD but presents a challenge especially in children due to overlap between normal and abnormal bleeding. Bleeding questionnaire (BQ) scores have been validated in adults and have recently been validated in children with VWD for assessing bleeding severity. However, there are limited data supporting their use prospectively in healthy children with bleeding complaints.

AIM

The objectives of this study were to obtain normative data from children and validate a paediatric BQ (PBQ) to determine the discriminative ability of its total score and its individual components for identifying children likely to have VWD.

METHODS

The PBQ was administered to 1281 multiethnic, healthy children between 30 days and 18 years of age presenting to a general paediatric office and to 35 children with VWD based on VWF antigen, activity and multimer pattern.

RESULTS

When children with total BQ scores of 3 or more were predicted to have VWD, the sensitivity was 97.2%, the specificity was 97.1%, the positive predictive value was 48.6% and the negative predictive value was 99.9%.

CONCLUSIONS

The PBQ may help discriminate a significant bleeding history from trivial bleeding, may be integrated into the primary care algorithm for evaluating children suspected with VWD.

Rare bleeding disorders - bleeding assessment tools, laboratory aspects and phenotype and therapy of FXI deficiency

Rare bleeding disorders (RBDs) are inherited deficiencies of coagulation factors such as fibrinogen, factor (F) II, FV, FVII, combined FV+FVIII, FX, FXI and FXIII. These disorders usually have a low prevalence in the general population and constitute approximately 3-5% of all coagulation disorders. However, in some countries they may have the same prevalence as haemophilia B due to the practice of consanguineous marriage. The clinical picture of RBDs is highly variable and can vary markedly from mild to severe, making both diagnosis and optimal treatment quite challenging. This review focuses on: (i) the efforts to establish a bleeding assessment tool adequate to RBDs, (ii) the optimal management of patients affected with FXI deficiency and (iii) the correlation between clinical severity and laboratory diagnosis when determining the minimum coagulant activity required to prevent bleeding in each RBD.

Newborn Screening for Glutaric Aciduria-II: The New England Experience

Newborn screening (NBS) using tandem mass spectrometry (MS/MS) permits detection of neonates with Glutaric Aciduria-Type II (GA-II). We report follow-up of positive GA-II screens by the New England Newborn Screening Program.

METHODS

1.5 million infants were screened for GA-II (Feb 1999-Dec 2012). Specialist consult was suggested for infants with two or more acylcarnitine elevations suggestive of GA-II.

RESULTS

82 neonates screened positive for GA-II, 21 weighing > 1.5 kg and 61 weighing ≤ 1.5 kg. Seven (one weighing < 1.5 kg), were confirmed with GA-II. Four of these had the severe form (died < 1 week). The other three have a milder form and were identified because of newborn screening. Two (ages > 5 years) have a G-Tube in place, had multiple hospitalizations and are slightly hypotonic. The third infant remains asymptomatic (9 months old). Two GA-II carriers were also identified. The remaining positive screens were classified as false positives (FP). Six infants (> 1.5 kg) classified as FP had limited diagnostic work-up. Characteristics and outcomes of all specimens and neonates with a positive screen were reviewed, and marker profiles of the cases and FP were compared to identify characteristic profiles.

CONCLUSION

In addition to the severe form of GA-II, milder forms of GA-II and some GA-II carriers are identified by newborn screening. Some positive screens classified as FP may be affected with a milder form of the disorder. Characteristic GA-II profiles, quantified as GA-II indexes, may be utilized to predict probability of disorder and direct urgency of intervention for positive screens.

Third Åland islands conference on von Willebrand disease, 26-28 September 2012: meeting report

The first meeting of international specialists in the field of von Willebrand disease (VWD) was held in the Åland islands in 1998 where Erik von Willebrand had first observed a bleeding disorder in some members of a family from Föglö and a summary of the meeting was published in 1999. The second meeting was held in 2010 and a report of the meeting was published in 2012. Topics covered included progress in understanding of VWD over the last 50 years; multimers; classification of VWD; pharmacokinetics and laboratory assays; genetics; treating the paediatric patient; prophylaxis; geriatrics; gene therapy and treatment guidelines. This third meeting held over 3 days covered the structure and function of von Willebrand factor (VWF); type 1 VWD, the most common form of the disease; a lifespan of pharmacokinetics in VWD; detecting inhibitors in VWD patients; and special challenges in understanding and treating the female VWD patient.

Malposition and expulsion of the levonorgestrel intrauterine system among women with inherited bleeding disorders

The levonorgestrel-releasing intrauterine system (LNG-IUS) is indicated for the management of menorrhagia and for contraception. The LNG-IUS is effective at reducing menstrual bleeding and improving haemoglobin among women with bleeding disorders. Expulsion rates for the LNG-IUS among normal women are reported to be approximately 5-10%. The aim of this study was to examine the malposition and expulsion rates of the LNG-IUS among women with inherited bleeding disorders. We conducted a retrospective study of women with an inherited bleeding disorder in Kingston, Canada treated with an LNG-IUS between May 2005 and June 2012. The primary outcome was a combined endpoint of expulsion and/or malposition. Predetermined secondary outcomes were patient satisfaction and changes in haemoglobin and ferritin levels. The median age of the women at the time of LNG-IUS insertion was 31 years (range 18-43, mean 32.1 years). The most common diagnosis was type 1 VWD (12/20, 60%). There were three LNG-IUS expulsions and two episodes of device malposition resulting in removal [5/20 (25.0%), 95% CI 11.2-46.9%]. An additional five women had their device removed prematurely. The overall proportion of devices resulting in discontinuation in this population was 10/20 (50.0%, 95% CI 29.9-70.1%). In this retrospective study, a significant proportion of women with an inherited bleeding disorder had an LGN-IUS removed due to poor patient satisfaction, malposition, or expulsion. Further studies into the causes of higher complication rates and interventions such as premedication or prolonged treatment with antifibrinolytic agents targeted at improving outcomes in this population are required.

Quantification of perioperative changes in von Willebrand factor and factor VIII during elective orthopaedic surgery in normal individuals

von Willebrand's disease (VWD) patients undergoing major surgery are prophylactically treated to promote haemostasis. There is variability in perioperative clinical practice; however, most guidelines suggest replacing the deficient factor to a level of 1.0 IU mL(-1) (or 100%). A review of the literature reveals a paucity of well constructed descriptive data quantifying the changes in coagulation that occur in response to surgical stress. The aim of this study was to quantify the changes in haemostatic variables occurring in response to elective orthopaedic surgery in normal individuals. Eligible subjects >18 years of age undergoing total hip or knee replacement were recruited. Blood samples were drawn at five time points: baseline, preoperatively, 30 min after surgical incision, 30 min postoperatively, postoperative day (POD) 1. Analyses included t-tests and repeated measures anova. Overall 30 patients, 21 women and 9 men, with a mean age of 65 were included in the final analysis. All von Willebrand factor (VWF) variables were seen to significantly decrease intraoperatively and increase postoperatively. VWF multimers showed a statistically significant decrease in high molecular weight multimers intraoperatively and an increase postoperatively. On subgroup analysis, age, gender and anaesthesia type were significantly correlated with changes in VWF parameters. Data presented in the current study establish a physiological baseline for VWF parameters in the normal population and demonstrate mean VWF/factor VIII levels greater than 1.0 IU mL(-1) intraoperatively. As such, current management in VWD patients does not appear to mimic the normal physiological response to surgery.

The genetics of Canadian type 3 von Willebrand disease: further evidence for co-dominant inheritance of mutant alleles

BACKGROUND

Type 3 von Willebrand disease (VWD) is the most severe form of the disease and is classically inherited in an autosomal recessive fashion.

OBJECTIVES

The aim of the current study was to investigate the molecular pathogenesis of a Canadian cohort of type 3 VWD patients.

PATIENTS AND METHODS

Thirty-four families comprised of 100 individuals were investigated. Phenotypic data, including bleeding scores (BS), von Willebrand factor (VWF) laboratory values and anti-VWF inhibitor status were included as well as sequence analysis.

RESULTS

We identified 31 different mutations (20 novel): 8 frameshift, 5 splice site, 9 nonsense, 1 gene conversion, 6 missense and 2 partial gene deletion mutations. The majority of mutations identified were in the propeptide (42%); index cases (IC) with these mutations exhibited more severe bleeding (BS = 22) than those with mutations elsewhere in VWF (BS = 13). Sixty-two out of 68 (91%) mutant alleles were identified. Twenty-nine IC (85%) had a VWF null genotype identified; 17 homozygous, 12 compound heterozygous. In five IC (15%), two mutant VWF alleles were not identified to explain the type 3 VWD phenotype. In four ICs only one mutant VWF allele was identified and in one IC no mutant VWF alleles were identified.

CONCLUSIONS

We have investigated the molecular pathogenesis of a Canadian cohort of type 3 VWD patients. Obligate carriers are not phenotypically silent in the Canadian population; 48% have been diagnosed with type 1 VWD. In approximately 50% of families in this study the inheritance pattern for type 3 VWD is co-dominant and not recessive.

A national analysis of complications following hemiarthroplasty for hip fracture in older patients

BACKGROUND

There is emerging evidence that patients with fractured neck of femur (FNOF) aged >85 years have different demands on a health-care system when compared to younger patients.

AIM

We sought to better quantify this in terms of comorbidity and complication rates.

DESIGN

Retrospective review of national database.

METHODS

Data on all patients who underwent hip hemiarthroplasty for FNOF between January 2005 and December 2008 were extracted from the English hospital episode statistics database.

RESULTS

There were 41 770 patients aged 65-84 years and 35 321 patients aged ≥85 years. The older cohort was less likely to have diabetes, chronic obstructive pulmonary disease and rheumatoid arthritis. However, they exhibited a significantly higher risk of lower respiratory tract infection [odds ratio (OR) = 1.58, 95% confidence interval (CI) 1.50-1.67)], myocardial infarction (OR = 1.67, 1.52-1.83) and acute renal failure (OR = 1.54, 1.40-1.70) within 30 days of surgery with an inpatient mortality risk at 90 days, double that of the younger age group. Length of stay (LoS) was significantly longer in patients >85 years compared to younger patients (median 18 days vs. 15, P < 0.001).

CONCLUSION

Patients aged ≥85 years admitted for FNOF were found to have a lower incidence of major chronic disease but exhibited a greater incidence of acute events following hemiarthroplasty and their LoS was increased. Targeted medical interventions that focus upon this susceptible patient group may help reduce morbidity and improve survival.

Endobronchial pulmonary cryptococcosis and tuberculosis in an immunocompetent host

Pulmonary cryptococcosis presenting as an endobronchial tumour-like growth has rarely been described. We report the case of a male patient with normal immune function who presented with a right upper lobe mass lesion. Bronchoscopy revealed a tumour-like growth that completely occluded the anterior segment of the right upper lobe bronchus. Bronchial biopsy and computed tomography-guided lung biopsy revealed Cryptococcus, and culture of lung biopsy specimen grew Cryptococcus neoformans and Mycobacterium tuberculosis. The patient responded clinically to amphotericin B, fluconazole and anti-tuberculous therapy. However, chest radiographic response was unremarkable. A presentation of pulmonary cryptococcosis and tuberculosis, along with endobronchial tumour-like growth in the same patient, is unusual and has not been previously described.

Relationship between diagnosis and intervention in women with inherited bleeding disorders and menorrhagia

Menorrhagia is the most common bleeding manifestation in women with inherited bleeding disorders. There is little known about whether the management of menorrhagia is altered in specific bleeding disorders. Optimizing treatment strategies for each specific diagnosis may improve quality of life in these women. This work aimed to look for a potential relationship between the specific diagnosis of an inherited bleeding disorder and the intervention required to control the menorrhagia. A retrospective chart review was performed for all women seen in the Kingston Women and Bleeding Disorders Clinic. Patients were categorized by diagnosis into two groups: Haemophilia carriers and all others. Treatment options were grouped into two categories: Medical or gynecological/surgical. Overall, 85.7% of haemophilia carriers required gynaecological surgical management, whereas only 31.4% of patients with all other diagnoses required gynaecological/surgical management (P = 0.012, Fisher's exact test). Therefore, carriers of Haemophilia were more likely to have a better outcome in treating their menorrhagia with gynaecological or surgical management compared with medical management. This information may 1 day help to guide treatment choice for menorrhagia in women with bleeding disorders.